The design and manufacture of vehicles are mature with well-established guidelines and standards to ensure the safety and flawlessness of the vehicles. However, the sleepiness or fatigue condition of the drivers is causing so many accidents and casualties that cannot be avoided by the toughness of the vehicles. In order to prevent the occurrence of vehicular accidents, more preemptive measures are required for achieving early detection of inattentive or drowsy driving.
According to the “Sleep in America” poll conducted by National Sleep Foundation (NSF), there were around 60% adult drivers admitted that they had driven a vehicle while feeling drowsy in the past year, which could be representing as many as 168 million drivers in the US. In 2014, the National Highway Traffic Safety Administration (NHTSA) had identified 846 fatalities that were drowsy driving related. This can be caused by the fatigue of the driver, the influences of drugs or alcohol, and other unexpected medical conditions, e.g., heart attack, stroke, etc. These dangerous situations are some of the major causes of road accidents in the US and other countries as well, posing significant risk and danger to the driver, other passengers, occupants of nearby vehicles and pedestrians.
In view of the issues raised above, various monitoring measures have hitherto been used or proposed to determine the attentiveness of the driver. Conventional methods use “steering pattern” and “steering torque” to analyze the mental state of the driver by detecting the steering pattern and lane-keeping behavior. However, the geometric characteristics of the road, weather conditions and road conditions may affect the steering angle and reduce the accuracy of the system. Another method is an image-based approach which captures the head pose, facial expression or eyes movement of the driver for determining whether the driver is awake or drowsy. However, the accuracy may also be affected by artifacts such as sunglasses or expressionless of the driver.
In some other applications, heartbeat sensors are embedded in the car seat to measure a driver's stress level. Typically, the car seat would monitor a driver's heartbeat through a plurality of sensors on the surface of the backrest that detect electrical impulses from the heart. Such a system has the intention to monitor the heart rate and alert when the driver may fall asleep at the wheel. However, embedding the sensors in the car seat increases the complication when installing and repairing. In most cases, such a system can only be integrated when manufacturing the car, and cannot be added to an existing car. The flexibility of the system is also limited and may not fit perfectly on all types of vehicles.
Accordingly, there is a need in the art for an in-vehicle monitoring and intervention system which overcomes the drawbacks of the prior art systems, provides accurate measurement of the drowsiness condition of a driver, and responds quickly to perform an intervention and alert the driver when the driver is in a drowsy state.